Vaccine-induced SIV Env-specific plasma IgG responses at week 9. (A) Plasma SIV gp140-specific IgG concentrations at weeks 0, 3, 6, and 9 in naive controls, noncontroller animals, and controller animals. The times of immunization and the vaccine constructs are indicated by arrows. (B) Plasma IgG concentrations for gp140, gp120, gp36, and gp70-V1V2 in controller and noncontroller animals at week 9, just prior to oral SIV challenge initiation. (C to E) Week 9 SIVmac251 neutralization titer (50%), ADP score, and avidity index for controller and noncontroller animals, respectively. (F) The correlation between anti-gp140 plasma IgG avidity at week 9 and acute viremia. (G) The gp140 plasma IgG avidity index for group B controller and noncontroller animals at the time of euthanasia. Nx, necropsy.